Control mechanism



1544,1941 4 w. A. EATON, 2,228,594

common MECHANISM Filed July is, 1959 Patented Jan. 14, 1941 UNITED" STATES PATENT OFFICE CONTROL MECHANISM Wilfred A. Eaton, Pittsburgh, Pa., assignor to Bendix-Westinghouse Automotive Air Brake Company, Pittsburgh, Pa. a corporation of Delaware Application July 13, 1939, Serial No. 284,371 10 Claims. (Ci. 19z 3) control mechanism controlled by manipulation' of the service brake control mechanism, motor speed control system and 'door control system.

A further object is to provide auxiliary brake control mechanism in connection with service brake control mechanism whereby the auxiliary system is rendered ineifective during certain conditions of service brake control operation.

Yet another object is to provide mechanism controlled by predetermined operations of the service brake control, door control and motor speed control mechanisms for applying and holding the brakes applied, and controlled by operation of-the motor speed control mechanism for' releasing the brakes. 7

Still another object is to'provide a structure of the abovecharacter wherein an auxiliary brake controlling mechanism may be electrically controlled in response to desired operations of the service brake, door, and motor speed control systems:

Other objects and novel features of the invention will appear more fully hereinafter from the following detailed description when taken in con nection with the accompanying drawing, It is to be expressly understood, however, \that the drawing is employed for purposes 01' illustration only and is not designed as a definition oi the limits of the invention, reference being bad for this purpose to the appended claims.

I In the drawing, the single figure of which 11- lust'rates diagrammatically, certain parts being shown in section, a vehicle control mechanism constructed in accordance with the principles oi.

the present invention, such mechanism is shown as applied to a motor vehicle of conventional type having a motor 6 for driving the vehicle and an accelerator 1 adapted to control the speed of the vehicle motor by virtue of its connection with throttle valve 8 through rod 9 and throttlelever arm 10. A spring I05 connected to the throttle lever arm l assists in moving theaccelerator to release position. In the illustrated embodi-' ment of the invention, the vehicle is provided with a service brake system comprising a reservoir I l adapted to receive fluid under pressure through a conduit I 2 from a suitable compressor, notshown, but preferably .idriven by the vehicle motor, and a brake cylinder I3 having a piston I4 for operating the vehicle brakes. and adapted to be supplied with-fluid pressure from reservoir I I under the control of'a manually operable brake valve IS, the valve being connected to the reservoir II by a conduit l6 and to the brake cylinder by 10 way of conduit l1, double check 'valve l8 and conduit IS. The brake valve is preferably of the selflapping type having an operating pedal and serving, on depression of the pedal, to establish communication between conduits i6 and I1 5 for supplying fluid under pressure from reservoir H to the brake cylinder l3 for moving piston Hi to the right and applying the brakes, andserving, on release of pedal 20, to connect the brake cylinder with atmosphere through conduit I9, 20

double check valve l8, conduit, I'I andan exhaust port 2| provided in the brake valve. It is to be understood that thedouble check valve I8 is so constituted as to normally permit communication between conduits l1 and I9, as will be more fully .5 explained hereinafter.

A door control system is provided having a fluid motor 22 adapted to operate a door of the vehicle,

-notshown, by means of a piston 23 connected to,

a door-operating shaft 24 through piston rod 25 and lever 26 operatively connected with the shaft, the parts described being normally maintained in door closing position by a spring 2-1 interposed between piston 23 and end wall 28 of the cylinder.

The motor is operated by fluid pressure from a reservoir 29 connected thereto by conduits 30 and 3|, a three-way valve 32 of conventional type having a valve control lever 33 and provided with an exhaust port 34 being interposed between said conduits and adapted with the 'control lever in 40 the position shown toconnect motor 22 with atmosphere through conduit 31, and adapted on movement of the control lever to another position to close the exhaust port and establish communication between conduits 30 and ll, thus permit- 5 ting fluid to flow from reservoir 29 to the motor and open the vehicle door. It is to be understood that reservoir 29 may be connected to a compressor on the vehicle or to. the other reservoirs through a conduit 35 in any convenient manner.

In order that the application and release or the .vehicle brakes may be controlled in response to manipulation of the service brake and door control systems, additional brake control means are provided including an auxiliary brake valve 36, pref- -mosphere through conduit i1 and the exhaust port of service brake valve 15 when the latter is in release position. The auxiliary brake valve 35 is also provided with an exhaust port 48 and operates when deenergized to exhaust fluid from brake cylinder l3 through conduit l8, double check valve I8 and conduit 38.

When stopping the vehicle, and particularly when stopping on an upgrade, it is customary for the operator to remove his foot from the accele'rator in order to apply the brake, and on completing the stop to open the vehicledoor to discharge or load passengers. The brakes must be held applied during this period, and on restarting vehicles of the type now in use the foot must be quickly shifted fromthe brake pedal to the accel erator if the start is to be made smoothly and without allowing backwardmovement of the vehicle andconsequent danger to following vehicles,

This operation is tiring to the driver,- and also involves the exercise of considerable skill, particularly in city vehicle operation where numerous tops are made and heavy traflic is encountered,

and, since, during this period, the accelerator is normally in released position and the vehicle door is opened, means are provided by the present invention for energizing the auxiliary brake valve under the control of means operable by release of the accelerator and by operation of the door control mechanism to open the vehicle door. While these two controls might inordinary cases be sufficient for the purpose of controlling a brake application by the auxiliary brake valve, there is always a possibility that the driver may inadvertently open the vehicle door when traveling at a considerable speed, whereupon release of the the fluid pressure in the brake system during a accelerator pedal might cause a very severe brake application dangerous to the passengers, and, as a further safeguard against such a contingency, additional control means are provided wherein service brake application controls the operation of theauxiliary brake valve, making it impossible for the driver to eflect an auxiliary brake application without ilrst making a service brake application, during which release of the accelerator and opening of the-vehicle door will insure operation of the auxiliary brake valve to eflect and maintain a brake application, which. can bereleased only by subsequent depression of the accelerator pedal.

Relatively simple and inexpensive mechanism is provided for accomplishing this desirable end, and, referring again to the drawing, it will be noted that. this mechanism includes a pair of switches 41 and 42 having normally closed and open contacts respectively, connected electrically in series relationship with a suitable battery 43 and with the electro-pneumati'c valve 36, and

operable -respectively by accelerator pedal, I

through rod 9, clamp, and resilient connection 45 and by the fluid pressurein the auxiliary brake control system-through a conduit 45 connected at one end to conduit 38 and at the other end to switch 41- A return connection between the switches is eflfected by ground wires 41 and 48 groundedon the vehicle, the other side of the electrical circuit comprising a conductor 48 be-" 5 tween switch 4| and battery 43, conductor 58 connected between the battery and the electropneumatic valve 36, and conductor 5| connected between the electro-pneumatic valve 36 and switch 42, the contacts 01' the two switches acting when closed to establish a complete circuit for I energizing the magnet valve. In order that the control heretofore described may be made fully eflective, a second pair ofpressure responsive serially connected switches 52 and 53, having normally open contacts, are provided, switch 52 'being actuated by fluid pressure from the door control system through conduit 54 connected to conduit 3|, and switch 53 being actuated by fluid pressure from the service brake system through a conduit 55 having a connection with conduit H. These switches are connected electrically by a conductor 56 and, by means of conductor 51 connected between switch 52 and conductor 5| and conductor 58 connected between switch 53 and a ground on the vehicle, are placed electrically in series relationship with switch 4|, battery 43 and electro-pneumatic valve 36, and in parallel relationship with switch 42, the result being that closing of switches 52 and 53 on closing of switch 42 will serve to complete the electrical circuit through electro-pneumatic valve 36' whenever the accelerator I is released to close switch 4|. In amplification of the foregoing description, reference is had to the patent to Wilfred A. Eaton, No. 2,141,689, dated December 2'7, 1938, for a more complete disclosure of devices equivalent to those used in the present invention, such as brake valve l5, double check valve l8, electro-pneumatic valve 36, and pressure responsive switches 42, 52 and 53. The brake valve l5 double "check valve i8, and electro-pneumati'c valve 36, of the present, application, are respectively similar to the devices 8, I5 and 48 shown in Figure 1 of the above referred to Eaton patent, while the pressure responsive switches 42, 52 and 53 may correspond to the switch 58 in Figure 1 of the above patent. I It will be readily apparent from the foregoing description that, during a normal brake application, the service brake valve l5 will be effective to supply braking fluid to brake cylinder I3 through conduit i1, double check valve 18 and conduit i8,'and to thepressure responsive switch 53 through conduits l1 and 55, but the resultant closing of switch 53'wii1 not complete the circuit through electro-pneumatic valve 36 until switches 4| and 52 are closed by subsequent release of the accelerator and opening of the vehicle door, so that all of the three above mentioned switches must be closed to effect energization of the electro-pneumatic valve 35. This condition normally exists-when the driver stops the vehicle by releasing the accelerator, making a service brake application, and then opening the vehicle door, whereupon switches Ii, 52 and 53 complete the circuit through valve 38, which in turn connects conduits 31 and 39 to supply fluid under pressure from reservoir 38 to double check valve l8. When this action occurs. the service brake valvemay be released and the fluid pressure in conduit 38 will operate the double check valve to disconnect conduits I! and I8 and connect conduits l8 and' 38, thus placing the brake cylinder l3 under the control of valve 35. It is desirable, however, to

control the release of the brake application above v aaaasea described by the accelerator alone, and the switch 42 provides means for accomplishing this desirable control, this switch being closedby fluid pressure supplied from valve 36 through conduits l8 and v 46, and acting in cooperation with switch 4| to maintain thecircuit between the battery 43 and valve 36 regardless of subsequent operation of the door control mechanism and service brake control systems with a resulting opening of switches 52 and 53..

' While an embodiment, of the invention illus-' trated in the drawing has been described with considerable particularity, it is to be understood that the invention is not restricted thereto, but

is capable of receiving a variety of expressions, some of which will now readilyv suggest themselves to those skilled in the art, while changes may be made in the details of construction and arrangement of parts, and certain features used without other features, without departing from the spirit of, the invention. Reference is, therefore, to be had to the claims hereto appended for a definition of the limits of the invention.

What is claimed is:

l. The combination in a motor vehicle havina leasing said power brake application.

3. The combination in a motor vehicle having service brake controlling means, door controlling means and an accelerator for controlling the speed of thevehicle motor, of power means controlled by said first two means and accelerator and efiective during a service brake application for rendering the power means effective to apply the brakes and to hold the brakes applied during subsequent operation of the first two means, and

controlled by said accelerator for releasingsaid power brake application.

4. The combination in a motor vehicle having a fluid pressure brake actuator and control means therefor, door controlling means and an accel-' erator for controlling the speed of the vehicle motor, of auxiliary brake actuator control means responsive to a predetermined operation of said first two named means and accelerator for rendering said actuator operative to eifect and maintain a brake application, and responsive to operation of said accelerator independent of the operation of said first two named means for releasing said brake application. 7

5. In a fiuld pressure brake system for amotor vehicle having door controlling means and throttle controlling means for the vehicle motor, a sourcc' of fiuid pressure, a brake actuator, means including a service brake. valve for controlling the fiow of fiuid to and from said actuator for applying and releasing the brakes,.an auxiliary brake valve having connections with said source and actuator for controlling the ficw of. fluid to and from said actuator, and means controlled by said first two named means and service brake valve for operating said auxiliary brake valve to supply fiuld pressure to said actuator and controlled by operation of said throttle control means for operating said auxiliary valve to release fiuid pressure from said actuator. a

6. The combination in a motor vehicle having a fluid pressurebrake actuator and control means therefor, door controlling means, an accelerator for controlling the speed of the vehicle motor and auxiliary brake actuator control means including an electro-pneumatic brake valve, of means operable in response to predetermined controlling of said first two named means and accelerator for energizing said electro-pneumatic valve to'eifect and maintains brake application, and responsive to operation of. said accelerator independent of subsequent operation of said first two named means for releasing said brake application.

'I. In a fiuid pressure brake system for a motor vehicle having door controlling means and throttle controlling means for the vehicle motor, a source of fiuid pressure, a brake actuator, means including a service brake valve for controlling the fiow of fluid to and from said actuator for J eflecting an' application and release of the brakes, an electro-magnetically operated auxiliary brake valve having connections with said source and actuator for controlling the fiow of fiuid to and from said actuator, and means including switches controlled respectively by operation of said first two named .means, service brake valve and auxiliary brake valve for energizing said valve to supply and continue to supply fluid to said actuator and controlled by said throttle controlling means onlyfor deenergizing said auxiliary brake valve to release fiuid from said actuator.

8. The'combination in a motor vehicle having service brake controlling means for applying and releasing the brakes, door controlling means and controlling'means for the vehicle motor, of means controlled by all of said means for applying and holdlng'the brakes applied and controlled by said j third named means for releasing the brakes.

9. The combination in a motor vehicle having service brake controlling means for applying and releasing the brakes, door controlling means and controlling means for the vehicle motor, of auxil iary brake applying means controlled by said second and third named means for efiecting a brake application, and means controlled by operation of the first named means for preventing the operation ofsaid auxiliary means for eirecting abrake application.

10. The combination in -a motor vehicle having service brake controlling means, auxiliary brake controlling means,'door controlling means and.

means for controlling the vehicle motor, of means controlled by the operation of said service brake controlling means, door controlling means and motor speed controlling means for controlling the operation of said auxiliary means to chest a brake application, an'dcontrol means operated by the brake applying action of the auxiliary means for holding the brakes applied and preventing the" release thereof by subsequent operation of said service brake controlling means and said door controlling means. 

